Before I use Nautilus as my default file manager, I also have a file manager called File. I changed File with Nautilus, but I don't know how to change File as my default file manager again.
Can you guys help me out? Thanks in advanced
To change the default file Manager, you can follow the instructions posted on How to set PcManFm as the default file manager?
All you need do is substitute pcman to file.
Hope this helps.